In a 3D display technology, as illustrated in FIG. 1, a parallax barrier 12 is disposed on a displaying side of a display panel 11 provided with a slit grating. Lights from an image displayed on pixels on the display panel 11 transmit to an observation point through the slits on the parallax barrier 12. As illustrated in FIG. 1, the pixels of the display panel which can be observed by a left eye 13 and a right eye 14 at the observation point are different, therefore the left eye 13 and right eye 14 of the observer at the observation point can see two different images, thus achieving a 3D display. An existing parallax barrier is generally made of a fixed pattern or a LCD. However, for the parallax barrier of the fixed pattern, after the parallax barrier is disposed on the display panel, the display panel can only perform 3D display, and can not be switched to 2D display. Therefore, the existing parallax barrier is usually made of the LCD.
As illustrated in FIG. 2, a parallax barrier made of the LCD known by the inventors comprises: two transparent substrate 21 and 22 cell-assembled together, and a liquid crystal 23 filled between the two transparent substrate 21 and 22. In order to form the slit grating for naked eye 3D display, a transparent conductive layer 24 and 25 are disposed on the two transparent substrate 24 and 25 respectively, and the upper conductive layer 24 is distributed continuously distribution to cover the whole panel, and the lower transparent conductive layer 25 is configured as signal electrode lines 252 and common electrode lines 251 arranged alternately. During operation, a driven voltage is applied to the signal electrode lines 252, and both the common electrode lines 251 and transparent electrode layer 24 are connected to a constant voltage source or the ground. An electric field is generated in a region where the signal electrode lines 252 oppose the transparent electrode layer 24 so as to drive the liquid crystal molecules to deflect so that the region is a light blocking region; whereas in a region where the common electrode lines 251 oppose the transparent electrode layer 24, because the voltage of the common electrode lines 251 is equal to that of the transparent electrode layer 24, the liquid crystal molecules in the region are not deflected, so that the region is a light transmitting region. The light blocking regions and the light transmitting regions are arranged alternately in the parallax bather, which is presented eventually as the slit grating for the naked eye 3D display. The common electrode lines 251 and transparent electrode layer 24 farther avoid a crosstalk between adjacent signal electrode lines 252 and other signal interference.
The inventors have found that in a parallax barrier with the above structure, the gap between the common electrode lines 251 and signal electrode lines 252 is very small (usually about 10 μm), which makes it easy to cause shorting due to problems of poor processing or dust particles, and seriously affects the product yield.